High prevalence and increasing incidence of multiple sclerosis in the Norwegian county of Buskerud
Multiple sclerosis (MS) is an inflammatory disease with secondary neurodegeneration that causes significant disability in young people over time.1 Norway has a high prevalence of MS and a long history of epidemiological studies. Swank2 was the first to evaluate the MS population size back in 1952 and found an annual incidence rate of 2.7/100 000 between 1935 and 1948. In a review article published in 2012, a nationwide prevalence of 165/100 000 and an incidence of 5.6/100 000 was estimated based on older epidemiological studies performed in Norwegian counties.3 The first nationwide prevalence study published in 2014 reported a prevalence of 203/100 000.4
The MS population in Buskerud has not been studied previously. The population is well defined with easy access to neurological services for decades, which allows us to follow the population over time. The aim of this study was to determine the prevalence and incidence of MS in Buskerud.